The present invention relates to a method of producing a molded part that is deep drawn from a thermoplastic thin sheet or foil.
DE 34 05 985 C2 discloses a method of producing a stamping or embossing roller for the continuous stamping or embossing of the outer surface of a thermoplastic foil, according to which, proceeding from a grained member in the form of a natural leather, the peripheral surface of the embossing roller is provided with a negative form of the depth structure of the natural leather member, and with the thus provided embossing roller, under the effect of heat and pressure, a thermoplastic foil is continuously embossed, whereby the embossed surface thereof is provided with the depth structure of the leather member in a positive form. It is known in general to convert such an embossed thermoplastic foil into spatial or three-dimensional molded parts by means of a deep drawing process, for example into interior decorative parts of motor vehicles.
During such a deep drawing process, the thermoplastic foil is stretched or expanded in different ways as a function of the spatial form of the molded part that is to be produced, so that the grained structure is also differently stretched. As a consequence, there results the drawback that the molded part that is produced has a varying appearance over its surface, which is not desirable. It is therefore an object of the present invention to provide a method of the aforementioned general type that avoids the drawbacks of the state of the art, and that improves the appearance of the deep-drawn molded part.